Particular groups of American Indians have increased annual incidences of SLE. These include Sioux, Crow and Arapaho tribes. Patients with SLE have anti T-cell antibodies and loss of subpopulation of T-cells. This subpopulation may regulate B-cell activity. In the absence of adequate regulatory function, excessive antibody forming cells are found. These cells have specificity for a variety of chemical haptens rather than just auto antigen.